1. Field of the Invention
The present invention relates to a sheet feeding device for use in a copying apparatus and a printer or the like.
2. Description of the Prior Art
In a conventional copying apparatus or a printer, there is provided a sheet feeding device for feeding a sheet of paper for printing having a plurality of sheet feeding cassettes for feeding paper of various sizes such as A3, B4, A4 and B5 sizes corresponding to a size of an original document. Referring to a way of carrying paper for printing from a sheet feeding device to e.g. a copying machine as a sheet receiving device, it is preferable from the viewpoint of sheet feeding speed to employ lateral feeding for feeding paper in a lateral direction thereof rather than to employ longitudinal feeding for feeding paper in a longitudinal direction thereof, and in the conventional copying machines, there is a kind of copying machine employing a lateral feeding also in the case of feeding paper of large size such as B4 and A3 sizes.
On the other hand, in the case that the lateral feeding is employed even when a sheet of large size such as A3 or B4 size is fed for printing, it is required to make a large-scaled photosensitive drum, sheet carrying roller and sheet carrying path provided in the copying machine so that the copying apparatus including these devices must be made large-scaled, resulting in raising the cost of the apparatus due to the large-scaled apparatus. Therefore, in general, there is employed a longitudinal feeding when sheets of a large size such as B4 and A3 sizes are fed and a lateral feeding is employed when a sheet of small size such as A4 or B5 size is fed.
However, in such a constitution as employed in a conventional apparatus, in a copying machine having a variable magnification/minification function, while it is required to provide two longitudinal sheet feeding types of cassettes B5R and A4R for feeding a small-sized sheet such as B5 and A4 sizes in a longitudinal direction of the sheet in a minification copying operation of an original document of A3 and B4 size for example, and it is also required to provide two lateral sheet feeding types of cassettes B5 and A4 for feeding a sheet of B5 and A4 sizes in a lateral direction thereof if considering the sheet feeding rate. Therefore, in order to provide various types of sheet feeding cassettes as mentioned above, it is necessary to provide a large-scaled sheet feeding device or to use a plurality of sheet feeding cassettes selecting one of the cassettes according to a size of printing sheet, resulting in that the apparatus must be made large-scaled and there is a problem that the cost thereof is increased and that the operation thereof becomes complicated.
Therefore, in order to solve the problems mentioned above, there have been previously proposed various sheet feeding devices as disclosed in the Japanese Patent Laid Open 56-59245 and in the Japanese Patent Laid Open 59-123859, in which a sheet feeding cassette for feeding a sheet of B5 size is common in use for both the cassettes B5 and B5R and another sheet feeding cassette for feeding a sheet of A4 size is common in use for both the cassettes A4 and A4R by rotating the cassettes respectively between the lateral feeding position and the longitudinal feeding position.
However, in the conventional sheet feeding device mentioned above, there is not considered a relationship between a rise/fall operation of a rotating plate for lifting the printing sheets and a rotating operation of a rotating cassette and there is a problem that the sheet disposed on the rotating plate interferes with other member of the apparatus when the rotating cassette is rotated, so that the rotating cassette can not be rotated properly.